The present invention relates to a method of baking carbon articles in a chamber. More particularly, this invention relates to a method of baking carbonaceous electrode materials of the type made of a mixture of calcined carbonaceous aggregate and a pitch binder.
It has been found that if the pitch content in the carbon electrodes is steadily increased, there comes a time when certain problems appear during the baking process. First of all, an increase in pitch binder content can lead to sticking problems between the articles as the pitch tends to exude somewhat from the articles as they are baked. Manual separation of bonded electrodes is costly timewise and leads to damaged electrodes which have to be scrapped. More importantly in the case of anodes for use in Hall-Heroult cells for producing aluminum, increasing the pitch binder content leads to distortion of the cross-section of the stub holes in anodes. This results in a poor fit between the steel stub and the anode and possible failure of the joint in the reduction cell.